1. Field of the Invention
The present invention relates to inkjet recording treatment liquids, inkjet cartridges, inkjet recordings, ink jet recording ink sets, and inkjet recording methods.
2. Discussion of the Background
Recently, inkjet printers have rapidly come into wide use, because such printers can print on regular paper, are easily used for colorization, are compact and inexpensive, and can be operated at relatively low cost.
On the other hand, inkjet printing often results in image defects, such as character feathering (hereinafter referred to as feathering), which can be attributed to certain ink compositions. Attempts to reduce feathering may involve suppressing ink permeability. However, suppression of ink permeability generally causes poor driability. As a result, when a user touches an image after printing, the image smears.
In inkjet printing, color images are printed by superimposing different colors of over one another. This process can result in bleeding of color ink at a color boundary portion of an image or non-uniform mixing of color inks (hereinafter referred to as color bleeding). These phenomena substantially decrease image quality. Attempts to address color bleeding may involve increasing ink permeability. However, suppression of ink permeability generally affects color ink so that the ink more easily enters into the recording medium. This, in turn, decreases image density and may cause the ink to permeate through to the back side of the recording medium. As a result, two-sided printing may not be suitably performed.
Attempts to address feathering and color bleeding have included image forming methods employing both an ink and a treatment liquid. While such methods have attempted to increase image quality, problems have arisen, including decreased driability of images and smearing, and unevenness in image density.
JP2004-142291 discloses a method in which a treatment liquid is dispensed onto a recording medium along with ink from an inkjet head. JP2004-330569 discloses a method in which a treatment liquid is sprayed onto a recording medium using air pressure. JP2008-260307 discloses a method in which a treatment liquid is applied to a recording medium by controlling application pressure of a coating roller and a counter roller.
The method described in JP2004-142291 raises difficulties because the viscosity and surface tension of the treatment liquid must be managed to allow dispensing via an inkjet head which requires particular limitations with respect to, e.g., nozzle diameter. The resulting treatment liquids have decreased driability.
The method described in JP2004-330569 raises difficulties because additional space must be provided in an image forming device for dispensing treatment liquid. In addition, in comparison to coating methods, it is difficult to control the amount of treatment liquid that is dispensed when spraying.
The method described in JP2008-260307 provides an insufficient improvement of feathering and color bleeding.